Pipe handling apparatuses are currently used in a number of applications. A gripping device as described herein is particularly useful on a platform deck, both onshore and offshore, for handling different pipes. Pipe handling apparatuses are normally used for a number of purposes on a platform deck, including:                moving pipes form one location to another on the deck, for example, from a storage location to a pipe assembly location or fingerboard;        lifting pipes from a horizontal storage position into a vertical position for screwing together with other pipes; and        holding pipes both horizontally and vertically.        
Previously described solutions exist, for example, in U.S. Pat. No. 2,964,020, US 2011/0148133 A1, and WO 02/074495 A1.
U.S. Pat. No. 2,964,020 describes a device for adjusting piston stroke in a power-driven drilling assembly. The piston stroke can be adjusted by rotating a nut relative to a shaft. The extent of the piston stroke is determined by the spacing between the nut and a sleeve fastened to the shaft. The stroke of the piston is reduced if the spacing between the nut and the sleeve is reduced.
US 2011/0148133 A1 describes a gripping assembly for handling pipes. The gripping assembly consists of two gripping members which are brought into gripping engagement with the outer circumference of a pipe. The opening of the gripping members or the distance between the gripping members defines the size of the gripping opening and is adjusted by a locking body. The locking body has a diameter that varies along the length of the locking body. The size of the gripping opening is determined by choosing the diameter that is to be brought into engagement between the two gripping members. A cylindrical piston is used to move the locking body relative to the gripping members to select diameter. The diameters at which the gripping members can work are given by the step wedge that is mounted in the gripping assembly. The gripping members stop against the diameter of the pipe around which they are gripping, which corresponds to one of the surfaces and the bevel edge.
WO 02/074495 A1 described a gripping claw for tubular goods comprising two, with respect to each other, pivotable jaws, and a working cylinder which causes a movement of the pivotable jaws with respect to a stationary housing. A counter block is arranged between the pivotable jaws in the housing. Each pivotable jaw is movably arranged with respect to the counter block by a forced motion. The movable forced motion causes an axial back and forth displacement which is simultaneous with the opening/closing of the pivotable jaws. The working cylinder is connected to each pivotable jaw via an articulated connection, thereby forming a pivot axis for the pivotable jaws.
A disadvantage of the solutions described in the prior art is a difficulty to quickly adjust the diameter of the jaws or gripping arms between different pipe diameters.